javascript - 是否有一个 JS 库可以根据特异性对 CSS 选择器文本进行排序？

Question

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Answer 1

在对您的问题的评论中，josh3736 链接 the W3C specification for determining specificity .如果您想要自己编写这样一个库(我鼓励您这样做，只是为了更多地了解它)，他们的方法似乎是一个很好的引用。

A selector's specificity is calculated as follows:

• count 1 if the declaration is from is a 'style' attribute rather than a rule with a selector, 0 otherwise (= a) (In HTML, values of an element's "style" attribute are style sheet rules. These rules have no selectors, so a=1, b=0, c=0, and d=0.)
• count the number of ID attributes in the selector (= b)
• count the number of other attributes and pseudo-classes in the selector (= c)
• count the number of element names and pseudo-elements in the selector (= d)

The specificity is based only on the form of the selector. In particular, a selector of the form "[id=p33]" is counted as an attribute selector (a=0, b=0, c=1, d=0), even if the id attribute is defined as an "ID" in the source document's DTD.

Concatenating the four numbers a-b-c-d (in a number system with a large base) gives the specificity.